PERFLUORINATED POLLUTANT PUZZLE

The saga of some pollutants starts with a synthetic chemical that is produced commercially for years before it is linked to health problems. Polychlorinated biphenyls (PCBs), widely used as insulating fluids for decades before they were banned in the mid-1970s, are an example.

A similar but more complicated story is emerging for the compound perfluorooctanoic acid. PFOA is used in the manufacture of fluoropolymers including DuPont's Teflon and in breathable, waterproof fabrics. During the . . .